Hello mb_qwerty,
Thank you so much for using our theme AcmePhoto. In this theme, header image is designed in a such way that if you place the small image, it will be occupy the whole are for the design purpose. So, we recommend you to use the image with the bicycle on the center. And in the case of title of the header part, it will not appeared on the mobile because of small screen size. We have lots of features on the free theme, hope you will enjoy with them. Please check all the available options on Appearance > Customize.
And you can follow the documentation for more details of the theme as well.
If you have any confusion, let us know. As per the above query, you can check our demos as well.
Regards
Acme Supports